Impaired interaural correlation processing in people with schizophrenia. (20th September 2021) - Zheng, Yingjun
Abstract: Detection of transient changes in interaural correlation is based on the temporal precision of the central representations of acoustic signals. Whether schizophrenia impairs the temporal precision in the interaural correlation process is not clear. In both participants with schizophrenia and matched healthy‐control participants, this study examined the detection of a break in interaural correlation (BIC, a change in interaural correlation from 1 to 0 and back to 1), including the longest interaural delay at which a BIC was just audible, representing the temporal extent of the primitive auditory memory (PAM). Moreover, BIC‐induced electroencephalograms (EEGs) and the relationships between the early binaural psychoacoustic processing and higher cognitive functions, which were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), were examined. The results showed that compared to healthy controls, participants with schizophrenia exhibited poorer BIC detection, PAM and RBANS score. Both the BIC‐detection accuracy and the PAM extent were correlated with the RBANS score. Moreover, participants with schizophrenia showed weaker BIC‐induced N1‐P2 amplitude which was correlated with both theta‐band power and inter‐trial phase coherence. These results suggested that schizophrenia impairs the temporal precision of the central representations of acoustic signals, affecting both interaural correlation processing and higher‐order cognitions. Abstract : The normal auditory system is able to maintain detailed arbitrary waveforms over a period of time (i.e., the primitive auditory memory, PAM) and to calculate the instantaneous interaural correlation leading to detection of a break in interaural correlation (BIC) even with an interaural time delay (ITD). People with schizophrenia showed a pervasive impairment in binaural temporal processing, not only in interaural correlation calculation but also the PAM extent. Importantly, the early‐stage psychoacoustic processing inability is associated with a degradation in N1‐P2 complex, theta‐band power and inter‐trial phase coherence (ITPC), and also contributes to higher‐order cognitive dysfunctions.